1. Field of Invention
The invention relates to a container for a liquid and, more particularly, to an ink cartridge for use in ink jet printers and other ink jet printing devices.
2. Description of Related Art
In a conventionally known ink cartridge for use in ink jet printers, an ink supplying hole and an atmosphere communication hole are formed in portions of a cartridge case, so that ink inside the cartridge case is supplied through the ink supplying hole to an ink jet recording head provided on the side of an ink jet printer. FIG. 9 shows an ink supplying hole 104 formed in a conventional ink cartridge 102.
To prevent ink leakage through the ink supplying hole 104 or an atmosphere communication hole (not shown in FIG. 9) during transportation, the ink supplying hole 104 and the atmosphere communication hole are sealed by sealing members during manufacture.
Before setting the ink cartridge into an ink jet printer for use, a user needs to peel the sealing members covering the ink supplying hole 104 and the atmosphere communication hole off from seal surfaces 106, 108 that surround the ink supplying hole 104 or those that surround the atmosphere communication hole.
The peeling load F needed to peel a sealing member from the seal surfaces 106, 108 surrounding the ink supplying hole 104 varies depending on position L as indicated in FIG. 10. For example, in a case where the peeling is started at a position S and completed at a position E, the peeling load F sharply decreases at the end position E. Such a sharp reduction in the peeling load F causes the sealing member to contract and curl in backlash movements due to its elasticity at the time when the sealing member peels off from the seal surfaces 106, 108 surrounding the ink supplying hole 104 and, particularly, when it peels off from the outer seal surface 108. In an example case wherein the adhesion force-decreasing rate relative to the peel distance exceeds 0.02 kgf/mm, the adhesion force reduction is too rapid for a user to correspondingly adjust the user's peeling hand action, resulting in a failure to prevent a backlash of the sealing member. In such a case, there is a danger that ink deposited on the sealing member covering the ink supplying hole 104 may spatter and stain the surroundings, i.e. the nearby area or items.
Ink spattering due to the backlash of a sealing member occurs because a person strongly grips and moves the sealing member until it peels off. It is very difficult to prevent the backlash of the sealing member by, for example, moving the hand in a direction generally opposite to the peeling direction of the sealing member at the instant when the sealing member peels off. Thus it is difficult to prevent ink spattering according to the known art.